Genetic Parameters of Test Day Measures for Somatic Cell Count, Milk Yield, and Protein Percentage of Milking Ewes

Baró, J.A.; Carriedo, J.A.; Primitivo, F. San

doi:10.3168/jds.s0022-0302(94)77207-6

Cited by 67 publications

(74 citation statements)

References 27 publications

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“…Ninane et al [11] verified the independence of their conversion for SCC at typical levels of somatic cells in raw cow's milk. However, somatic cells are naturally higher in raw sheep's milk there [2] (Tab. IV) and they might, in counts ≥ 1 000 000 SCC·mL -1 , have an effect on the enumeration of bacterial cells by BSC-FC [16].…”

Section: Methods Describing Criteriamentioning

confidence: 99%

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The application of flow cytometry in determining the bacteriological quality of raw sheep’s milk in Slovakia

Tomáška

Suhren²,

Hanuš

et al. 2006

Lait

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-In this study enumeration of bacterial cells in raw sheep's bulk milk by an automated flow cytometry method (Bactoscan FC) was evaluated. The results were discussed with respect to the results obtained by the analysis of cow's milk. Within-laboratory reproducibility, which depended on the counting level, was slightly worse than that of raw cow's milk (valued in the interval > 50 Individual Bacterial Cell (IBC)·µL -1 ). In routine procedure, if preceding samples had counts > 20 000 IBC·µL -1 , then this was observed to increase the count of the following sample significantly in many cases ("carry-over"). Bactoscan counts were moderately enhanced with increasing numbers of somatic cells in sheep's milk. However, this trend was indicated only in samples with lower plate counts (< 10 5 colony-forming units (CFU)·mL -1 ). The regression equation between the results of the anchor plate method and the Bactoscan method was computed from the sample set which represented sheep's milk production in Slovakia during 2004 (data between percentiles 1 and 99, n = 877): log 10 CFU·mL -1 = 1.088 log 10 IBC·µL -1 + 2.292; with an accuracy of the estimate, expressed as standard deviation of regression s y,x = 0.305 log 10 CFU·mL -1 . The actual regression for raw cow's milk was verified, introducing both raw cow's milk samples and raw sheep's milk samples. The transformation of IBC·µL -1 to CFU·mL -1 realised by various published conversions was evaluated by testing of the parallelism of the regression lines and also by comparison of obtained differences on a model data set. The conclusions support the requirement to set up a special conversion for the intended field of application at any time. Résumé -L'application de la cytométrie de flux pour déterminer la qualité bactériologique du lait cru de brebis en Slovaquie. Dans cette étude, la numération des cellules bactériennes a été évaluée dans le lait cru de brebis de grand mélange par la cytométrie de flux automatisée (Bactoscan FC). Les résultats ont été comparés à ceux obtenus sur le lait de vache. La reproductibilité interne au laboratoire augmentait avec le niveau de la numération et était légèrement inférieure à celle obtenue sur lait cru de vache (pour les valeurs > 50 cellules bactériennes individuelles (CBI)·µL -1 ). La méthode de routine a montré que si les échantillons précédents avaient un niveau de contamination > 20 000 CBI·µL -1 , cela pouvait fréquemment augmenter significativement les valeurs dénombrées dans l'échantillon suivant ("carry over"). L'augmentation des cellules somatiques dans le lait de brebis entraînait une légère augmentation des valeurs de dénombrements par Bactoscan. Cependant cette tendance n'a été observée que dans les échantillons ayant les plus faibles niveaux de dénom-brements sur boîte (< 10 5 unités formant des colonies (UFC)·mL -1 ). L'équation de régression entre les résultats de dénombrements sur boîte et de dénombrements par Bactoscan a été calculée à partir de l'ensemble des échantillons représentant la production du lait de b...

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Section: Methods Describing Criteriamentioning

confidence: 99%

“…Therefore, raw sheep's milk was examined here. Its biological, physical and chemical properties differ from raw cow's milk [1,2].…”

Section: Introductionmentioning

confidence: 99%

The application of flow cytometry in determining the bacteriological quality of raw sheep’s milk in Slovakia

Tomáška

Suhren²,

Hanuš

et al. 2006

Lait

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“…Heritability estimates, based on repeatability test-day models, range from 0.04 to 0.16 for several breeds including the Churra (Baro et al, 1994;El-Saied et al, 1998;Othmane et al, 2002), the Manchega (Serrano et al, 2003), the East Friesian (Hamann et al, 2004) and the Valle del Belice sheep breeds (Riggio et al, 2007). Other studies reported similar or slightly higher heritability estimates (from 0.11 to 0.18) for the average SCS during lactation, for Chios (Mavrogenis et al, 1999), Lacaune (Barillet et al, 2001;Rupp et al, 2003a), Latxa (Legarra and Ugarte, 2005) and Manech Red Faced ewes (Barillet et al, 2008).…”

Section: Genetic Parameters Of Scc and Mastitis In Sheepmentioning

confidence: 99%

“…Published genetic correlations between SCS and milk yield range from positive, i.e. antagonistic, to negative (Baro et al, 1994;El-Saied et al, 1998, 1999Barillet et al, 2001;Rupp et al, 2003a;Riggio et al, 2007).…”

Section: Genetic Correlations Between Scs and Other Traitsmentioning

confidence: 99%

Genetic selection for reduced somatic cell counts in sheep milk: A review

Riggio

Portolano

2015

Small Ruminant Research

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a b s t r a c tMastitis is an inflammation of the udder, mainly caused by bacteria, and leads to economic loss, due to discarded milk, reduced milk production, reduced milk quality and increased health costs in both dairy sheep and cattle. Selecting for increased genetic resistance to mastitis can be done directly or indirectly, with the indirect selection corresponding to a prediction of the bacteriological status of the udder based on traits related to the infection. The most frequently used indirect method is currently milk somatic cell count (SCC) or somatic cell score (SCS). This review reports the state of the art relating to the genetic basis of mastitis resistance in sheep and explores the opportunities to use SCC as selection criterion in a breeding programme to improve resistance to mastitis in sheep, discussing the actual situation and prospects for improvement. It has been stressed, in particular, that although it is unlikely that selection for mastitis resistance by the farmers on their own will be successful, there is good prospect for genetic improvement if reliable pedigree and performance recording is implemented across flocks, combined with breeding value estimation. To achieve this, a strong and well-structured organization to implement and support the programme is essential.

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“…Nevertheless, in the context of bovine selection strategies aimed at reducing the incidence of mastitis, investigations have been performed to evaluate the genetic relationships between veterinary-treated mastitis, SCC and milk production. Heritability of mastitis is low (0.024) while the heritability of SCC is moderate (0.17) [1,2,5]. However, the genetic correlation between the two traits is strong (0.72), suggesting a similar genetic determinism part [51].…”

Section: Management Practicesmentioning

confidence: 99%

Potential uses of milk epithelial cells: a review

2002

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-Secretions collected from the mammary gland of different species contain heterogeneous populations of cells including lymphocytes, neutrophils, macrophages and epithelial cells in different species. Several factors influence the somatic cell count in milk and the distribution of cell types, such as species, infection status, physiological status and management practices. The epithelial cells are shed into milk during the lactation process. Most of them are viable and exhibit the characteristics of fully differentiated alveolar cells. Primary cultures of epithelial cells from colostrum and milk of humans, baboons, cows and goats together with established cell lines from human and goat milk, provide a good model for the study of lactogenesis, immunity transmission, cancer research and infection by viruses. The RNA extracted from milk cells have been shown to be representative of gene expression in the mammary gland and thus provide a source of material for molecular studies of gene expression and environmental interactions. milk / somatic cell count / epithelial cellsRésumé -Utilisations potentielles des cellules épithéliales du lait. Les sécrétions de la glande mammaire de différentes espèces, contiennent une population hétérogène de cellules incluant des cellules du système immunitaire et des cellules épithéliales. Divers facteurs influencent le nombre de cellules somatiques dans le lait et la distribution de chaque type cellulaire, en particulier l'espèce, le stade physiologique, l'état sanitaire et les conduites d'élevage. Les cellules épithéliales se détachent de l'épi-thélium mammaire au cours du processus de sécrétion du lait. Cependant, une grande majorité d'entre elles sont viables et présentent des caractéristiques de cellules alvéolaires totalement différenciées. En culture primaire ou en lignées cellulaires, elles constituent un modèle d'étude de l'action hormonale, de marqueurs de la cancérogenèse, de la transmission de l'immunité et d'infections virales. Les ARN totaux extraits des cellules du lait constituent une source de matériel représentatif de l'expression des gènes dans la glande mammaire et devraient permettre des études globales d'expression des gènes en interaction avec l'environnement de l'animal. lait / numération cellulaire / cellule épithéliale Reprod. Nutr. Dev. 42 (2002) 133-147 133

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Genetic Parameters of Test Day Measures for Somatic Cell Count, Milk Yield, and Protein Percentage of Milking Ewes

Cited by 67 publications

References 27 publications

The application of flow cytometry in determining the bacteriological quality of raw sheep’s milk in Slovakia

The application of flow cytometry in determining the bacteriological quality of raw sheep’s milk in Slovakia

Genetic selection for reduced somatic cell counts in sheep milk: A review

Potential uses of milk epithelial cells: a review

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